Shuttle damage detection still uncertain

According to a USA Today article, NASA is still not certain that new sensors can detect damage to the space shuttle while in orbit.

Shuttle crews need a way to check the orbiter for possible damage while in space, and a contingency must be available to the astronauts in case a shuttle is damaged after launch. These are key requirements of a NASA safety panel overviewing the agency's readiness to return the shuttle to service.

NASA's plan is to use two sensors mounted on the shuttle's remote manipulator arm to detect possible damage to the orbiter's protective tiles. However, there is some question over how small an area the sensors can examine effectively.